This invention relates generally to the human brain, and more particularly, to modification of the state of being of the human brain by use of an audio signal.
It is known that the brain operates at different frequencies. These frequencies are generally classified in different regions, for example, the Delta, Theta, Alpha, and Beta brain states. Specifically, the lowest frequency is the Delta brain state which is the sleep state and which is believed to operate in a 2 to 4 Hz region. The next state is a Theta state which is a deep meditative state and operates in the region of 4 to 7 Hz. After the Theta state, there is the Alpha state which is a normal non-active wakeful or idle state and operates in the 7 to 14 Hz region. Finally, the Beta state is the normal active state and operates in the region greater than 14 Hz and possibly as high as 40 Hz.
In many instances, a person is operating in one brain state and desires to be in another brain state. For example, people with insomnia have difficulty entering the lower brain states to fall asleep. In the opposite regard, it may be difficult for people to wake up completely and enter a normal active state in the Beta region.
Many chemicals, legal and illegal substances, such as coffee, nicotine, alcohol, tranquilizers, sleeping pills, amphetamines, and the like, are traditionally used to create these states. The side effects and possible addiction to these substances is well-known.
Therefore, the need and desire is very strong and there has been a great search for techniques and/or external stimuli which can vary the brain state. Much has been written about the benefits of relaxation and stress reduction. Stress has been shown to contribute to heart attacks, and is known to suppress the normal operation of the immune system, thus leaving the body vulnerable to attack from many serious illnesses. See "A New Prescription: Mind over Malady" by Rob Welchsler, Discover Magazine, February, 1987.
Another such article is The "Physiology of Meditation", Scientific American, by Robert Keith Wallace and Herbert Bensen, February, 1972, Volume 226, No. 2, Pages 84-90. This article discusses the use of transcendental meditation for varying the brain state, and discusses the various tests for determining the change in brain states, including skin resistance to an electric current, heartbeat, the rate and volume of respiration and an electroencephalogram pattern.
Different approaches have been made with respect to varying the brain state of a person. For example, various audio systems are commercially sold using subliminal messages in order to coax the brain into a different state. Examples of such systems are those sold by Zygon, 1420 Northwest Gilman Boulevard, Suite 2655, Issaquah, Wash. 98027; Outer Skin Performance, P.O. Box 7597, Beverly Hills, Calif. 90212-7597; and Effective Learning Systems, Inc., 5221 Industrial Boulevard, Edina, Minn. 55435. However, such subliminal messages, even when coupled with environmental sound and/or music, as is conventional, are insufficient to vary the brain state of a person.
It has also been suggested that the brain state of a person can be changed or driven by exposing the eye to flickering lights. Specifically, at a certain rate of flicker, it is suggested that the Alpha rhythm changes from its original rhythm to that of the flickering light. See, for example, Adler's Physiology of the Eye, Chapter 13, "Visual Pathways", Page 444. However, this brute-force method of changing the brain state has never been put into practice and is rarely successful.
In like manner, it has been suggested that the use of an audio signal in a similar manner will produce a similar result. This suggestion has been made in an article "The Monroe Institute's Hemi-Sync Process--A Theoretical Perspective" by F. Holmes Atwater, August, 1988. As discussed therein, the author indicates that a beat frequency can be produced inside of the brain by supplying signals of different frequencies to the two ears of a person. As a result, binaural beats are produced and are perceived by the brain as a result of the interaction of auditory signals within the brain. Such binaural beats are not produced outside of the brain as a result of the two audio signals of different frequencies. In a sense, the binaural beats are similar to beat frequency oscillations produced by a heterodyne effect, but occurring within the brain itself. However, the article discusses the use of such binaural beats in a strobe-type manner. In other words, if the brain is operating at one frequency, binaural beats of a fixed frequency are produced within the brain so as to entice the brain to change its frequency to that of the binaural beats and thereby change the brain state. However, as discussed above, this brute-force method is rarely successful.
It is also known that there are methods of attaching electrodes to the brain and inducing various stimuli. For example, there is an "electro sleep" method where a mild current is passed through the temples. This method is not approved in this country. "Electro shock" treatments use the same input, but with larger currents. Another treatment induces an alternating current of various frequencies to electrodes attached behind the ears. These methods are invasive and need to be administered by a physician.